Method of manufacturing a one piece fusible connector



1966 1. F. MATTHYssE' 3,231,966

\ METHOD OF MANUFACTURING A ONE PIECE FUSIBLE CONNECTOR Filed July 26,1962 INVENTOR.

United States Patent 3,231,966 METHQD 0F MANUFACTURING A ONE PIECEFUSIBLE CGNNECTOR Irving F. Mattliysse, Danbury, Conu., assignor toBurndy Corporation, a corporation of New York Filed July 26, 1962, Ser.No. 212,686 1 Claim. (Cl. 29-4555) This invention relates to a method ofmanufacturing a high capacity fuse connector which is essentially anelectrical connector provided with a fusible element.

Considerable economy can be had in forming the fusible element out ofthe same piece of metal forming the body of the connector. This may beaccomplished by taking a tubular piece of copper and flattening acentral portion thereof which is subsequently blanked into the size ofthe fusible section required. The thickness of the fusible section soprovided is twice the wall thickness of the tubular piece of copper.

It is an object of the invention to provide an increased arc chillingand deionizing ability of the fuse section above described. A furtherobject is to accomplish the foregoing as economically as possible andpreferably without the necessity of adding new parts to the fusestructure.

These and other objects of my invention are accomplished and new resultsobtained as will be apparent from the device described in the followingspecification, particularly the method pointed out in the claim andillustrated in the accompanying drawing in which:

FIG. 1 is a plan View partly in section of a one piece connector with aflattened fusible portion all made of tubular stock;

FIG. 2 is a side elevation of the same;

FIG. 3 is a similar view partly in section with the fusible portionspread apart and disposed in an arc quenching medium; and

FIG. 4 is a cross sectional view of the connector of FIG. 3 taken alongthe line 44.

The fusible connector 10, illustrated in FIGS. 1 and 2, is made of apiece of copper tubing of the desired diameter thickness and length.

Depending on the connection sought, either one end or the centralportion of the tubing is flattened. In the connector illustrated, thecentral portion after flattening is thereafter blanked into the desiredshape forming a laminated fusible element 12 from which the conductorreceiving tubular portions 14 extend.

The fusible device so described is known in the power transmission artas a limiter. As an example, a limiter made from copper tubing having anoutside diameter of 1.060 inches, and a wall thickness of 0.113 inch,when 3,231,966 Patented Feb. 1, 1966 operating at 480 volts, has aninterrupting capacity of about 30,000 amperes when contained in a heatresistant enclosure filled with quartz sand.

Unexpectedly, by merely spreading apart the laminations of the fusibleportion constituting the flattened walls of tube, the interruptingcapacity will be nearly doubled.

Specifically, in FIG. 3 the laminations 16 and 18 comprising the fusibleportion 12 are spread apart a distance of about /2 inch, which will formtwo parallel paths. The distance is sufficient to cause an ample amountof the quartz sand 20 to enter between the laminations nearly doublingthe surface area exposed to the sand. A heat resistant enclosure 22 isprovided to retain the arc quenching material 20 in place. This willgreatly increase the arc chilling and deionizing ability of the limiter.

The resulting fusible connector achieves a substantial increase incurrent interrupting capacity without an increase in cost.

I have thus described my invention, but I desire it understood that itis not confined to the particular forms or uses shown and described, thesame being merely illustrative, and that the invention may be carriedout in other ways without departing from the spirit of my invention and,therefore, I claim broadly the right to employ all equivalentinstrumentalities coming within the scope of the appended claims, and bymeans of which objects of my invention are attained and new resultsaccomplished, as it is obvious that the particular embodiments hereinshown and described are only some of the many that can be employed toattain these objects and accomplish these results.

I claim:

The method of forming a fusible connector which comprises the steps oftaking a hollow tubular piece of metal, flattening a central portion ofsaid piece, blanking the flattened portion to a desired shape, spreadingapart the layers of the flattened portion to provide a plurality ofspaced apart fusible elements, and surrounding the entire surface ofsaid fusible elements with a filler material.

References Cited by the Examiner UNITED STATES PATENTS 1,221,275 4/1917Bleecker 200-132 2,259,053 10/1941 Xenis 200--135 2,988,620 6/1961Kozacka 200- FOREIGN PATENTS 452,156 8/1936 Great Britain.

BERNARD A. GILHEANY, Primary Examiner.

